An ideal front projection screen uniformly reflects light from one or more projectors to a distribution of viewers. The projection surface should be free from any spatially resolvable non-uniformities or defects that may be perceptible to the viewers. Any such features may overlay the intended content and detract from the viewing experience. Unfortunately, due to methods of construction and due to audio requirements, a typical cinema screen may typically incorporate at least two such sources of defects. Because of the difficulty of manufacturing a single unbroken expanse of substrate large enough to comprise a screen, most screens are manufactured by seaming together roll stock. The change in surface reflectivity across the seam and the gap between adjacent sheets should be sufficiently small that it is substantially imperceptible to the audience.
Additionally, in many cinemas, speakers are typically located behind the screen for front-channel audio. In order to achieve acoustic transmission through the screen, the screen is typically perforated with an array of holes. Again, the array of holes should be small enough that it is not visible to the audience. The seams and perforations individually present a challenge to the maintenance of an optically uniform surface, however the combination of these two effects provide an even more difficult challenge; the interruption of the perforation pattern by the seam can render an otherwise unobjectionable perforation pattern highly visible. Furthermore, the presence of the perforations may limit the techniques in which the screen may be seamed together.